One of the challenging issues in Ad hoc wireless networks is to identify methods that increase their lifetime. Since, the advancements in the battery technologies are negligible compared to those that take place in the field of mobile computing, the demand for discovering alternate methods to improve the battery lifetime has considerably increased. Energy efficient protocols face the trade-off between throughput improvement and energy saving. We, in this paper, arrive at a unique benchmark parameter called Nominal Capacity per Packet Transmission (NCPT) for evaluating the energy efficiency of a protocol. Major contributions of this paper are: (a) a detailed description of the novel distributed homogeneous Battery Aware MAC (BAMAC(k)) and Heterogeneous Battery Aware MAC (HBAMAC) protocols, which take benefit of the chemical properties of the batteries and their characteristics, to provide fair node scheduling and increased network and node lifetime through uniform discharge of the batteries, (b) a discrete-time Markov chain analysis for batteries of the nodes, and (c) a thorough comparative study of our protocols with IEEE 802.11 and DWOP (Distributed Wireless Ordering Protocol) MAC protocols. We found that our protocols outperform IEEE 802.11 and DWOP MAC protocols, in terms of power consumption, fairness, and lifetime of the nodes. Extensive simulations have shown that our protocol extends the battery lifetime consuming 96% and 60% lesser percentage of NCPT compared to the IEEE 802.11 and the DWOP MAC protocols, respectively.